Gastric Helicobacter pylori infection is diagnosed based on histopathological evaluation of gastric mucosal biopsies, urease test, urea breath test, H. pylori culturing, or direct detection using polymerase chain reaction (PCR). This study aimed to evaluate the efficacy of immunohistochemical (IHC) staining in detecting H. pylori in gastric biopsies from patients with chronic gastritis and minimal or atypical infection. Gastric biopsies from 50 patients with chronic gastritis were subjected to routine haematoxylin and eosin (H&E), modified Giemsa, and IHC staining. The results of staining were compared with those of quantitative real-time PCR (qRT-PCR). The qRT-PCR analysis identified 32 (64%) H. pylori-positive cases, whereas IHC, H&E, and modified Giemsa staining identified 29 (58%), 27 (54%), and 21 (42%) positive cases. The sensitivity of IHC staining (87.50%) was higher than that of H&E (59.38%) and modified Giemsa (43.75%) staining. The specificity of H&E, modified Giemsa, and IHC staining was 55.56%, 61.11%, and 94.44%, respectively. IHC staining exhibited the highest diagnostic accuracy (90%), followed by H&E (58%) and modified Giemsa (50%) staining. Active gastritis, intestinal metaplasia, and lymphoid follicles were detected in 32 (64%), 4 (8%), and 22 (44%) cases, respectively, and all of these cases were H. pylori positive. In contrast to routine H&E and modified Giemsa staining, IHC allows for the accurate H. pylori detection in cases with minimal or atypical infection. Moreover, IHC can be an alternative diagnostic method to qRT-PCR for detection of H. pylori in such cases.

胃幽门螺杆菌感染的诊断基于胃黏膜活检组织病理学评估、尿素酶试验、尿素呼气试验、幽门螺杆菌培养或使用聚合酶链反应 (PCR) 的直接检测。本研究旨在评估免疫组织化学 (IHC) 染色在检测慢性胃炎和轻微或非典型感染患者胃活检中幽门螺杆菌的功效。对 50 名慢性胃炎患者的胃活检进行常规苏木精伊红 (H&E)、改良吉姆萨染色和 IHC 染色。将染色结果与定量实时 PCR (qRT-PCR) 的结果进行比较。qRT-PCR 分析鉴定了 32 (64%) 种幽门螺杆菌-阳性病例，而 IHC、H&E 和改良吉姆萨染色确定了 29 (58%)、27 (54%) 和 21 (42%) 例阳性病例。IHC染色的敏感性（87.50%）高于H&E（59.38%）和改良吉姆萨染色（43.75%）。H&E、改良吉姆萨染色和 IHC 染色的特异性分别为 55.56%、61.11% 和 94.44%。IHC 染色表现出最高的诊断准确性 (90%)，其次是 H&E (58%) 和改良的吉姆萨 (50%) 染色。活动性胃炎、肠化生和淋巴滤泡分别在 32 例（64%）、4 例（8%）和 22 例（44%）病例中检测到，并且这些病例均为H. pylori阳性。与常规 H&E 和改良吉姆萨染色相比，IHC 允许准确检测幽门螺杆菌在极少或非典型感染的情况下进行检测。此外，在这种情况下，IHC 可以作为 qRT-PCR 的替代诊断方法，用于检测幽门螺杆菌。